Controlling the crystallization and magnetic properties of melt-spun Pr2Fe14BÕa-Fe nanocomposites by Joule heating
نویسندگان
چکیده
Pr2Fe14B/a-Fe based nanocomposites have been prepared through crystallization of melt-spun amorphous Pr7Tb1Fe85Nb0.5Zr0.5B6 ribbons by means of ac Joule heating while simultaneously monitoring room-temperature electrical resistance R. The R value shows a strong variation with respect to applied current I, and is closely related to the amorphous-to-nanocrystalline phase transformation. The curve of R versus I allows one to control the crystallization behavior during Joule heating and to identify the heat-treatment conditions for optimum magnetic properties. A coercivity of 550 kA/m and a maximum energy product of 128 kJ/m have been obtained upon heating the amorphous ribbons at a current of 2.0 A. These properties are around 30% higher than the values of samples prepared by conventionally ~furnace! annealed amorphous ribbons. © 2004 American Institute of Physics. @DOI: 10.1063/1.1757017#
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